Poly(ethylene glycol) (PEG) as a Reusable Solvent Medium for Organic Synthesis. Application in the Heck Reaction
S. Chandrasekhar*, Ch. Narsihmulu, S. Shameem Sultana and N. Ramakrishna Reddy
*Organic Chemistry Division-I, Indian Institute of Chemical Technology,
Hyderabad 500 007, India, Email: srivaric
iict.ap.nic.in
S. Chandrasekhar, C. Narsihmulu, S. S. Sultana, N. R. Reddy, Org. Lett., 2002, 4, 4399-4401.
DOI: 10.1021/ol0266976
Abstract
Low molecular PEG has been used as a solvent for a ligand-free Heck reaction with easy recyclability of solvent and Pd catalyst. The reaction works well for electron-deficient and electron-rich olefins with high regio- and stereoselectivities.
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Details
The document discusses the use of poly(ethylene glycol) (PEG) as a solvent medium for the Heck reaction, a type of Pd-catalyzed C-C bond formation. PEG, particularly with a molecular weight of 2000 or lower, was found to be an efficient reaction medium, offering high yields, rapid reactions, and easy recyclability of both the solvent and the Pd catalyst. The study highlights PEG's advantages over traditional volatile organic solvents and ionic liquids, including better regio- and stereoselectivities. The Heck reactions were tested with various substrates, such as bromobenzene and ethyl acrylate, yielding high-purity products. PEG also acted as a phase-transfer catalyst (PTC), eliminating the need for additional PTCs or ligands. The solvent and catalyst could be reused multiple times with consistent yields, demonstrating PEG's potential as a sustainable and efficient medium for organic synthesis. The research was supported by CSIR and CEFIPRA, with acknowledgments to referees for their recommendations.
Key Words
ID: J54-Y2002-270
